Botley to London Terminals starting at Southampton Airport Parkway

[RailyGood]

Is it valid to use a Botley to London Terminals ticket starting at Southampton Airport Parkway?

I was travelling with others who claimed this would be no problem on a service that first stopped at Winchester. Being cautious, I bought a ticket from Southampton Airport to Winchester despite having the Botley to London ticket. When the guard came to check our tickets, after the train had called at Winchester, he marked the Botley to London tickets, and I specifically asked him if these tickets were valid if we got on at Southampton Airport Parkway, and he said yes. I didnt even show him I'd bought the Southampton Airport to Winchester ticket.

Is this valid? Did I need to buy the other ticket? If it is valid, what is the reasoning? I cant see how it is a valid route, and national rail claim you need to buy 2 tickets to make the journey from Botley via Southampton Airport

 

[ForTheLoveOf]

I'm not particularly familiar with the railway geography down there, so please be understanding if I make a mistake. However, I think the guard was right in the context of a season ticket - however, had it been a non-season ticket then I think it may have been an invalid route, depending on exactly which route the train from ex-Southampton Airport train took.

One of the appropriate origin Routeing Points for a Botley-London ticket is Eastleigh. Map combination XR+RG makes this valid via Southampton on a non-season ticket if you go via Romsey (and avoiding Winchester), or on a non-season ticket on any of the routes covered by map XR in that area (as you can trace non-doubling-back routes through all the lines and may start late and stop short an unlimited number of times).